QUIZ: How do your manners stack up?

DON'T put your elbows on the dinner table. Always eat asparagus with your hands (unless the vegetables are sauced or not firm). And never, ever, brush your hair in public. In the modern age, the rules of etiquette are very easy to laugh at. I know where my elbows are during dinner: in the face of the person sitting next to me as I try to take a perfect photo of my food for my Instagram profile (#SorryNotSorry). So long as the conversation is flowing and everyone is enjoying themselves, who the hell cares where my elbows are?

But if I - and you - feel that way, where does it leave the providers of etiquette classes, the finishing schools and the publishers of books on good manners? In a world where every day is dress-down, and we all eat from bowls, they must be struggling, no?

Well actually, no. Take Debrett's, whose Peerage was first printed in 1769. In the past century, it moved into who's-whos and guides on everything from entertaining to modern manners. Last year, it teamed up with high-society magazine Tatler to create a new etiquette course at its Training Academy - promising to bestow "grace" and "effortless style and charm", no matter what the situation.

It has a website, dispensing handy tips on double-kissing and Christmas cards ("a fun, ironic photo may be better received than anything too posed"). And now it's even addressing the digital narcissism to which all seem to have succumbed. For example: when taking selfies with celebrities, "the nature of the selfie makes it difficult not to encroach on your subject's personal space, but a hug might be overdoing it".

The social bible doesn't comment on scene-stealing an Instagram video, as the Queen did with Prince Harry the other day. But if she had, there'd be no end of clicks, says Desmond So, the founder of East-West Institute of Applied Etiquette in Hong Kong. According to him, the inter-connectedness of our world has prompted a huge surge of interest in how to behave Downton-style.

With more affluence comes more dinner parties, and the need to know how to host them, he says; with iPhones comes the problem of whether or not to stick your tongue out in a Snapchat selfie. Seriously. As Dhiraj Murthy, a reader in sociology at Goldsmiths University, London, confirms.

"Etiquette is highly relevant to social media as it is all about what is considered normal and acceptable," he says. "Some social processes were more elite in the past, like eating in a restaurant. As social activities become more democratic, practices of etiquette can do so as well.

"Think of it this way. If someone drops food on the floor during a meal at home and then picks it up and eats it, only those there know about it. But if such behaviours are in tweets and Instagram photos, the action has a much wider audience. For some, the five-second rule applies; for others, such behaviour is repugnant."

That's a clarion call to Dr Rachel Rich - a senior lecturer at Leeds Beckett University and an expert in the cultural history of European dining - for whom "etiquette is all about the class system". And it's all down to the need in medieval and early modern courts to differentiate rich from poor, and to modify the behaviour of battle-hardened knights at royal courts.

"There are books from the Middle Ages encouraging people not to blow their nose on the table cloth. That's what etiquette was: teaching you how to hold yourself in," she says. And it was misogynistic, she continues. Setting rules for the smallest details of social behaviour - such as when ladies should take off their gloves - might seem an amusing quirk of British society on the surface, but such etiquette was also used to closely police women.

Dr Rich explains that, in the 19th century, it was unacceptable for women to have an appetite or appear greedy during formal dinners, and they were therefore not allowed to help themselves to food or drink. Instead, women had to be served by the man sitting next to them - "and if the man next to her wasn't considerate enough to offer, a woman might end up sitting there and not eating at all".

Of course, to a digital - erm - native, this may all seem so totally-like-old-skool as to be irrelevant. But in an era of fat-shaming, trolling and swipe-lefts, there does seem a need for some kind of self-imposed rules. After all, none of us wants to be disgraced by a viral video. It would be like taking off your gloves to serve yourself at a Victorian dinner party.

How good are your manners?

Take the quiz based on Debrett's advice below to find out

You were late to a friend's dinner party. Do you...

A // Say sorry and send a hand written note of apology after dinner

B // Say sorry

C // Send a note of apology

You're at a restaurant and your soup is too salty, but the waiter just asked if everything is okay. Do you....

A // Ask if you can have something different from the menu

B // Beam at him and say the food is delicious

C // Mutter something unintelligible

Your drunk friend is demanding another drink at a party and their behaviour is embarrassing both themselves and others. Do you ...

A // Give them another drink and call for a taxi

B // Forbid them from drinking anymore

C // Shout at them for being such a disgrace

You're at a social event and you need a wee - where do you say you are going?

A // The toilet

B // The loo

C // The bog

You're in a taxi and the driver won't stop talking. Do you...

A // Contribute the odd assenting murmur and let the monologue wash over you

B // Pretend to call someone you work with

C // Tell him to shut up

You're serving tea to some friends. Do you...

A // Pour the tea then add milk

B // Leave it for your guests to add themselves

C // Add milk to the cup first

You're hosting a dinner party and the last guest has outstayed their welcome. Do you...

A // Tell them you're exhausted and haven't recovered from a long journey you took the other day

B // Tell them to bugger off

C // Pretend to fall asleep and hope they leave

You've bumped into someone you were introduced to last week and you can't remember their name. Do you...

A // Apologise in a charming, self-deprecating way

B // Call them 'Fred' and hope for the best

C // Pretend not to remember meeting them

You sent an email meant for your mum to your boss by accident. Do you...

A //Call your boss and ask them to ignore/delete the email

B // Pretend it didn't happen

C // Quit your job immediately

You're at a party and the person you're talking to is a massive bore. Do you...

A // Listen for a few minutes, say "how fascinating, but don't let me monopolise you" and introduce them to someone else